! File: 4487C.PROP ! Database: PEPDB ! Date: 22-FEB-1994:14:20:35 coverpage: title_1: UV EMISSION LINE FORMATION PROCESSES AROUND THE title_2: BRIGHTEST HERBIG AE STAR HD104237 sci_cat: COOL STARS sci_subcat: EARLY EVOLUTION proposal_for: GO pi_title: DR. pi_fname: ALEXANDER pi_lname: BROWN pi_inst: U. OF COLORADO pi_country: USA pi_phone: (303) 492-7810 keywords_1: HERBIG AE STAR hours_pri: 3.71 num_pri: 1 hrs: Y funds_amount: 28000 funds_length: 12 funds_date: DEC-93 pi_position: SENIOR RES ASSOCIATE off_fname: CARL off_lname: WIEMAN off_title: CHAIRMAN off_inst: JOINT INSTITUTE FOR LABORATORY ASTROPHYSICS off_addr_1: UNIVERSITY OF COLORADO off_addr_2: CAMPUS BOX 440 off_city: BOULDER off_state: CO off_zip: 803090440 off_country: USA off_phone: (303) 492 5128 off_telex: (303) 492 5235 ! end of coverpage abstract: line_1: Herbig Ae stars are intermediate mass pre-main sequence (PMS) stars, and line_2: the more massive counterparts of the well-known T Tauri stars. Their line_3: evolution and atmospheric properties are still poorly understood. We line_4: propose to study the profiles of emission lines formed in the outer line_5: atmosphere/ circumstellar regions of the brightest and closest Herbig Ae line_6: star, HD104237, using GHRS spectra at moderate and high resolution of line_7: selected high temperature emission lines. At present it is not clear if line_8: these lines form in a classical transition region (TR)/chromosphere, a line_9: stellar wind, or an accretion disk (probably the least likely alternative) line_10: The emission line profiles will be analyzed to investigate atmospheric line_11: (density and temperature structure) and wind (mass loss rate, velocity line_12: and density laws) properties of this star. One goal is to discover if line_13: the winds from Herbig Ae stars can totally dominate the atmospheric line_14: structure of the star with TR plasma forming an integral part of the line_15: stellar wind or if physically separate, stationary, confined regions line_16: exist at the base of the wind. We shall determine quantitative line_17: constraints on the non-radiative heating and mass loss processes in the line_18: atmosphere, which will allow a better understanding of the evolution of line_19: PMS stars, since the heating and mass loss are driven by processes line_20: related to the sub-photospheric stellar structure. ! ! end of abstract general_form_proposers: lname: BROWN fname: ALEXANDER title: PI inst: COLORADO, UNIVERSITY OF country: USA ! lname: LINSKY fname: JEFFREY mi: L. inst: COLORADO, UNIVERSITY OF country: USA ! ! end of general_form_proposers block general_form_text: question: 3 section: 1 line_1: Our proposed observations will provide the first high-quality (S/N = 15- line_2: 100) line profiles for emission lines of H I (1216A), Si III (1206A), line_3: O V (1218A),O I (1302,4,6 + S I, Si II), C II (1335A), Si IV (1396,1403A) line_4: O IV (1402,1407, C IV (1548,1550A) and Mg II (2796,2803A). All of these line_5: spectra will be obtained with the G160M grating, except for Mg II which line_6: will be obtained with ECH-B. line_8: The observations requested are: line_9: Central Strong line_10: GHRS grating Wavelength(s) Aperture Exposure S/N Features line_11: Time line_12: G160M 1216 LSA 11 min 30 H I/Si III/O V line_13: G160M 1302 LSA 12 min 30 O I/S I line_14: G160M 1335 LSA 20 min 15 C II line_15: G160M 1400 LSA 45 min 31 Si IV line_16: 10 O IV line_17: G160M 1550 LSA 34 min 20 C IV line_18: ECH-B 2799 LSA 5 min 100 Mg II line_19: The quoted signal-to-noise values refer to the peak of the strongest line_20: emission line in the particular spectrum. The large dynamic range and line_21: low noise of the GHRS ensures that many weak features can be seen in line_22: the requested exposures. 1335 EXPOSURE REMOVED TO FIT ALLOCATION. ! question: 4 section: 1 line_1: The data required for this program consists of UV spectra not obtainable line_2: from the ground. IUE has been used extensively to study this target to line_3: the limits of its capability (including high resolution exposures up to line_4: 16 hours), and further observational advances depend on the acquisition line_5: of higher S/N spectra with GHRS. The increased sensitivity, wavelength line_6: resolution, dynamic range and S/N characteristics of the GHRS over those line_7: obtainable with the IUE (Carpenter et al. 1992, Ap.J. Lett., 377, L45.) line_8: will allow more accurate and detailed modelling of physical processes line_9: occurring in the outer atmosphere of HD104237. Only the GHRS is capable line_10: of providing us with the high precision line profiles, fluxes, and line_11: absolute velocities required for our program. ONLY GHRS CAN PROVIDE line_12: THE LINE PROFILES OF OPTICALLY-THIN, DENSITY-SENSITIVE EMISSION LINES. line_13: .. line_14: The exposures requested are summarized in section 2. The exposure times line_15: have been estimated using absolute fluxes previously measured with the line_16: IUE. For the first order and echelle gratings we used sensitivity values line_17: given in the GHRS instrument handbook. The LSA is used, because it line_18: provides sufficient resolution for our requirements and post-processing line_19: of the spectra can recover some of the resolution lost due to the large line_20: point spread function filling the LSA. ! question: 5 section: 1 line_1: No real-time observations or special scheduling is required. ! question: 6 section: 1 line_1: We require the high wavelength accuracy to measure flow velocities in the line_2: chromosphere, wind and circumstellar shell of our target star (down to line_3: the 1 km/sec level in the medium and echelle observations). We also line_4: require the best possible wavelength calibration to aid in the line_5: identification of weak features. These requirements mean that we need line_6: calibrations good to better than 0.3 diode. Experience with SV and SAO line_7: data has demonstrated that the default calibration will produce line_8: uncertainties of up to 3 diodes due to magnetic and thermal drifts within line_9: the spectrograph. Using internal Pt lamp spectra taken during SPYBALs, line_10: we can estimate the amount of drift and can therefore reduce the line_11: degree of uncertainty to about 0.5 diodes. To obtain the greatest line_12: possible wavelength accuracy, about 0.1 diodes, we require dedicated line_13: WAVECAL exposures using the internal Pt lamps to be connected to each line_14: GHRS science exposure. The wavelength calibrations must be taken at the line_15: same carrousel position and close in time to the science exposures to line_16: remove uncertainties caused by the GIMP and thermal drifts which move line_17: the image around on the GHRS photocathode. ! question: 7 section: 1 line_1: The data will be reduced and analyzed with in-house software developed line_2: for analysis of IUE and GHRS data. Software developed by the GHRS IDT line_3: will be used to optimize the calibration of the observations. Line line_4: widths, profiles, and wavelengths will be carefully measured to extract line_7: information on the velocity structure of the outer atmosphere, including line_8: both random non-thermal velocities and systematic flows. Relative and line_9: absolute fluxes will be measured to estimate densities and temperatures line_10: in the outer atmosphere. Methods for analyzing cool star emission line line_11: spectra are well established. Emission measure analysis can be used to line_12: model chromospheric and transition region structure. A general line_13: discussion of the methods is given by Jordan and Brown (1981) and an line_14: example of its application to a PMS star is given by Brown,Ferraz and line_15: Jordan (1984) in their analysis of T Tau. Other PMS stars that we line_16: have modelled with these same methods include HD 283572, a PMS G star line_17: studied by Walter et al. (1987), and our analysis of HR5999 and BN Ori line_18: (The et al,1985; Brown et al, 1986, 1992). Density-sensitive, O IV and line_19: O V lines will provide esimates of the TR electron density and accurate line_20: representations of the velocity field in the formation regions, since line_21: these lines will be optically thin. If any hot accretion disk line line_22: emission is present, it should be very broadened and show stronger line_23: shortward flux dure to occulation effects. ! question: 8 section: 1 line_1: None. ! question: 9 section: 1 line_1: GO Program 3626 - Empirical determination of the wind velocity and line_2: density laws for the K supergiant Zeta Aurigae from eclipse ingress line_3: Spectra (A. Brown PI, J. Linsky, R. Weyman, D. Reimers, R. Baade, line_4: T. Kirsch) ! question: 10 section: 1 line_1: Software developed by the GHRS IDT and the proposers will be used in the line_2: reduction and analysis of these observations. A workstation at JILA line_3: connected to the CASA cluster is available for data reduction and line_4: analysis. ! !end of general form text general_form_address: lname: Brown fname: Alexander title: Dr. category: PI inst: Joint Institute for Laboratory Astrophysics addr_1: University of Colorado city: Boulder state: CO zip: 803090440 country: USA phone: (303) 492-7810 telex: 755842 JILA ! ! end of general_form_address records fixed_targets: targnum: 1 name_1: HD104237 descr_1: A,127 pos_1: RA=11H57M33.47S+/-0.15S, pos_2: DEC=-77D54'50.5"+/-0.5" equinox: 1950 pm_or_par: Y pos_epoch_bj: B pos_epoch_yr: 1950.00 ra_pm_val: -0.016200 ra_pm_unct: 0.001000 dec_pm_val: 0.0140 dec_pm_unct: 0.0070 rv_or_z: V=0.0 fluxnum_1: 1 fluxval_1: V=6.5 ! ! end of fixed targets ! No solar system records found ! No generic target records found exposure_logsheet: linenum: 10.000 targname: HD104237 config: HRS opmode: ACQ aperture: 2.0 sp_element: MIRROR-A2 num_exp: 1 time_per_exp: 1.8S priority: 1 param_1: SEARCH-SIZE=3, param_2: BRIGHT=RETURN req_1: ONBOARD ACQ FOR 12; req_2: CYCLE 3/10-46 ; req_3: GROUP 10-46 NO GAP comment_1: STEP TIME = 200 MSEC comment_2: EXPECTED A2 COUNTS ARE comment_3: APPROX. 300 PER STEP TIME ! linenum: 12.000 targname: HD104237 config: HRS opmode: ACQ/PEAKUP aperture: 2.0 sp_element: MIRROR-A2 num_exp: 1 time_per_exp: 162.3S fluxnum_1: 1 priority: 2 req_1: ONBOARD ACQ FOR 20.0-46.0 comment_1: STEP-TIME=1.6 SEC comment_2: CENTER IN LSA AFTER NEW DEFCAL ! linenum: 20.000 targname: WAVE config: HRS opmode: ACCUM aperture: SC2 sp_element: G160M wavelength: 1222.50 num_exp: 1 time_per_exp: 54.4S priority: ^ param_1: STEP-PATT=3 req_1: CALIB FOR 21 NO SLEW; req_2: SEQ 20-21 NO GAP comment_1: NO CARROUSEL MOTION BETWEEN 20 AND 21 ! linenum: 21.000 targname: HD104237 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1222.5 num_exp: 2 time_per_exp: 354.0S priority: ^ param_1: STEP-PATT=5 ! linenum: 25.000 targname: WAVE config: HRS opmode: ACCUM aperture: SC2 sp_element: G160M wavelength: 1302.0 num_exp: 1 time_per_exp: 54.4S priority: ^ param_1: STEP-PATT=3 req_1: CALIB FOR 26 NO SLEW; req_2: SEQ 25-26 NO GAP comment_1: NO CARROUSEL MOTION BETWEEN 25 AND 26 ! linenum: 26.000 targname: HD104237 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1302.0 num_exp: 2 time_per_exp: 354.0S priority: ^ param_1: STEP-PATT=5 ! linenum: 35.000 targname: WAVE config: HRS opmode: ACCUM aperture: SC2 sp_element: G160M wavelength: 1401.0 num_exp: 1 time_per_exp: 54.4S priority: ^ param_1: STEP-PATT=3 req_1: CALIB FOR 36 NO SLEW; req_2: SEQ 35-36 NO GAP comment_1: NO CARROUSEL MOTION BETWEEN 35 AND 36 ! linenum: 36.000 targname: HD104237 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1401.0 num_exp: 7 time_per_exp: 354.0S priority: ^ param_1: STEP-PATT=5 ! linenum: 40.000 targname: WAVE config: HRS opmode: ACCUM aperture: SC2 sp_element: G160M wavelength: 1548.0 num_exp: 1 time_per_exp: 54.4S priority: ^ param_1: STEP-PATT=3 req_1: CALIB FOR 41 NO SLEW; req_2: SEQ 40-41 NO GAP comment_1: NO CARROUSEL MOTION BETWEEN 40 AND 41 ! linenum: 41.000 targname: HD104237 config: HRS opmode: ACCUM aperture: 2.0 sp_element: G160M wavelength: 1548.0 num_exp: 6 time_per_exp: 354.0S priority: 2 param_1: STEP-PATT=5 ! linenum: 45.000 targname: WAVE config: HRS opmode: ACCUM aperture: SC2 sp_element: ECH-B20 wavelength: 2800 num_exp: 1 time_per_exp: 32S priority: ^ param_1: STEP-PATT=3 req_1: CALIB FOR 46 NO SLEW; req_2: SEQ 45-46 NO GAP ! linenum: 46.000 targname: HD104237 config: HRS opmode: ACCUM aperture: 2.0 sp_element: ECH-B20 wavelength: 2800 num_exp: 1 time_per_exp: 300S priority: ^ param_1: STEP-PATT=7 ! ! end of exposure logsheet ! No scan data records found